From c96edcdc79e73bd15a0d752021ea0c8b4ee0d332 Mon Sep 17 00:00:00 2001
From: DIYgod <i@diygod.me>
Date: Wed, 17 Aug 2022 01:40:00 +0100
Subject: [PATCH] feat: custom domain dns check

---
 src/lib/tenant.server.ts | 13 +++++++++++--
 src/pages/_middleware.ts |  4 ++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/lib/tenant.server.ts b/src/lib/tenant.server.ts
index 683d315f..bb06e671 100644
--- a/src/lib/tenant.server.ts
+++ b/src/lib/tenant.server.ts
@@ -1,6 +1,6 @@
 import { OUR_DOMAIN } from "./env"
 
-export const getTenant = (request: Request, search: URLSearchParams) => {
+export const getTenant = async (request: Request, search: URLSearchParams) => {
   const host = request.headers.get("host")
 
   if (!OUR_DOMAIN) {
@@ -21,7 +21,16 @@ export const getTenant = (request: Request, search: URLSearchParams) => {
       return subdomain
     }
     if (host !== OUR_DOMAIN) {
-      return host
+      const res = await fetch(
+        `https://cloudflare-dns.com/dns-query?name=_xlog-challenge.${host}&type=TXT`,
+        {
+          headers: {
+            accept: "application/dns-json",
+          },
+        },
+      )
+      const txt = await res.json()
+      return txt?.Answer?.[0]?.data.replace(/^"|"$/g, "")
     }
   }
   return
diff --git a/src/pages/_middleware.ts b/src/pages/_middleware.ts
index 9abefe10..5a2ca1ac 100644
--- a/src/pages/_middleware.ts
+++ b/src/pages/_middleware.ts
@@ -12,7 +12,7 @@ const ALWAYS_REPLAY_ROUTES = [
   "/api/logout",
 ]
 
-export default function middleware(req: NextRequest) {
+export default async function middleware(req: NextRequest) {
   const { pathname } = req.nextUrl
 
   if (pathname === "/favicon.ico") {
@@ -39,7 +39,7 @@ export default function middleware(req: NextRequest) {
     })
   }
 
-  const tenant = getTenant(req, req.nextUrl.searchParams)
+  const tenant = await getTenant(req, req.nextUrl.searchParams)
 
   if (pathname.startsWith("/api/") || pathname.startsWith("/dashboard")) {
     return NextResponse.next()